Bolted connections are found in civil systems such as buildings and bridges, in transportation devices such as trains and airplanes and automobiles, and in power distribution systems as examples.
A power flow control system is an exemplary system, developed for attachment of power flow control devices to transmission lines for load balancing purposes. The devices comprise impedance injection modules that are inserted in series into the transmission line. Each impedance injection module comprises components connected in series, and each of these series connections typically comprises one or more bolts. Clearly, a failure of such a bolted series connection will break the current in the transmission line, and this will represent a system failure. Thus, one of the biggest risks to a power flow control system is that a bolted connection may loosen, and the associated electrical connection will fail.
Accordingly, there is a need in the art for bolt monitoring systems that can be applied to bolted connections in general, and to live electrical connections in particular, to provide early warning of potential system failures.